Comment 7 for bug 448268

The file /var/lib/dpkg/alternatives/cli is certainly truncated ( size of 0 )

Remove that file (just move it to another place)
$ sudo mv /var/lib/dpkg/alternatives/cli ~/

You can then the broken file by running :
$ sudo update-alternatives --install /usr/bin/cli cli /usr/bin/mono 10 --slave /usr/share/man/man1/cli.1.gz cli.1.gz /usr/share/man/man1/mono.1.gz
$ sudo update-alternatives --auto cli

Then try performing the upgrade of mono-jit again.

I hope this helps.